Your credit score, which will greatly impact your ability to qualify for a loan with better terms

From there, there are a few ways to manage your loan:

Option 1: Refinancing

If you're stuck with a high-interest auto loan, you might consider refinancing for a new auto loan with better terms. Banks, credit unions and online financial institutions may be able to get you a new loan with terms more favorable than the original one.

Ideally, the new loan term will be shorter than the current one. The point is to pay off the car note as quickly as possible, in order to pay as little interest as possible.

Depending on your original rate, however, a longer-term loan might still mean less interest paid overall. Falcone knows of a Navy enlistee who financed a car at a dealer for a whopping 24%. Fortunately, she was able to refinance at 7%.

Run your own numbers through an auto loan refinance calculator like this one from LendingTree, the parent company of MagnifyMoney. If your original agreement includes a prepayment penalty or if the new loan would carry an origination fee, you'll need to factor those into your calculation as well.

If you can refinance at a lower interest rate, early payoff will become easier.

Option 2: The rapid repayment route

The faster you retire a loan, the less interest you'll pay. One simple tactic to pay off a loan quickly is to make biweekly payments instead of monthly payments.

If you owe $430 per month, for example, you'd make half that payment every two weeks. Paying $215 every other week (or 26 times per year) rather than the full amount 12 times a year would add up to $5,590 instead of $5,160.

You could also continue to make monthly payments, but pay more than the required amount. An easy way to start is by rounding up. For example, if you owe $389 per month, you could make the payment $400 (or more, if you can).

Where to find the extra money? These tactics can help:

Sell stuff. A game system, designer purse, mountain bike or other rarely used items could bring in decent dollars through eBay, Craigslist or consignment websites.

Write down what you spend. Small, unnoticed expenses can add up fast, says Brian Hanks, a certified financial planner who practices in Salt Lake City. He advises clients to keep track of all expenditures for a month (on paper or with an app). Often, they're startled to discover how much the things they "don't get real value out of" are costing them each month - money that could be applied to their loans.

"Once they realize it, behavior can change," said Hanks.

Get a side hustle. Petsitting, driving for Lyft, a weekend waitressing gig - whatever fits your ability and personality. Or use your professional skill set to become a consultant, looking for work you can do on weekends.

Contribute windfalls. You got a tax refund. Grandma sent you $50 for your birthday. Vacationing neighbors paid you to pick up their mail. Any time additional money shows up, throw it toward your payment.

Ask for a loan. A relative or friend might be willing to help. Draw up an agreement specifying how you'll repay (weekly? monthly? by cash, check or PayPal?) and then keep to the terms.

"Prove that you have the savings gusto in you for a month," he said. Then, put the money saved toward the next payment. Often, the spending freeze "reframes what they thought was a 'need' into a 'want,'" said Andrews, who specializes in working with millennials. This means more money for the loan every month.

Before you start making extra payments, talk to the lender. You need to make absolutely sure that the additional money goes against the principal of the loan.

Option 3: Selling and starting over

Want to get out from under a loan entirely? Let someone else pay it off.

Compare the Kelley Blue Book value to the amount you still owe. If there's a positive balance - say, you owe $10,000 and it's worth $11,000 - then put the car up for sale.

Once you have a buyer, ask the lender for the payoff amount: What it will take to pay in full and get the vehicle's lien released. Smith-Valentine suggests creating a written agreement stating that the third-party buyer will pay the lender directly, and you will sign over the title once you receive it.

You'll want to have another mode of transportation lined up, of course. Having to carpool or take public transit for a while might be preferable to being deeply in debt. Continue to make your "car payment," though: Set aside that amount every month for a replacement vehicle. Figure out what you're not paying for car insurance and add to the car fund, too.

If the agreed-upon sale price doesn't cover the payoff amount, be prepared to make up the difference. Should you be lucky enough to sell the car for more than it's worth, use the balance as seed money for a replacement car.

A word of caution about auto trade-ins: You may have seen ads for auto dealers who offer to pay off your previous loan if you'll trade in the vehicle for a new one. The Federal Trade Commission advises consumers to be cautious about such deals, especially if they have negative equity (aka they're "underwater" on their loans).

Some of those dealers find ways to include the money owed that in the new agreement - which means you would be financing that negative equity along with the cost of the replacement vehicle. Read the contract very carefully, and ask for an explanation of how any negative equity was handled.

What if you're underwater on your auto loan?

Owing more than a vehicle is worth makes it tougher to sell but not necessarily impossible.

If you have savings, make up the difference between what a buyer will pay for the car and what will be left on the auto loan afterward. No ready cash? Look into taking out a small personal loan to pay off the remaining balance. It may be better to owe some money than to be stuck with a large loan for a vehicle that continues to depreciate.

Another possibility: Make extra payments against the principal until the loan balance matches the car's value, and then put it up for sale. Before you do, check to see if at that point you'll be eligible for refinancing at a better rate - if you want to keep the car, that is - and if you'll be able to swing the lower payments.

Should you give back the car?

Suppose you're underwater, can't refinance, have no savings and are disgusted with the thought of making payments for years. It can be tempting to just give the car back to the dealer.

Don't do it. A "voluntary repossession" reduces costs only for the creditor, and will hurt you in the long run.

The now-used car will probably sell for less than the loan balance, and you are required to pay the difference. For example, if you still owe $12,000 and the vehicle sells for $9,000, then you'll have to come up with the "deficiency" of $3,000. You'll also be on the hook for other funds, such as fees associated with the repossession, including storage and legal fees.

The lender can sue you for a "deficiency judgment," which shows up on your credit report. If the account gets turned over to a collections agency, you'll be hounded nonstop - and the judgment will remain on your credit report until it's paid. The repossession will also stay on your report for up to seven years, which wreaks havoc on your credit score.

Instead of giving the car back, use the rapid repayment tactics noted above to bring the loan balance closer to the vehicle's current value. At that point, try selling or refinancing. If you're financially stressed, Smith-Valentine suggests a longer finance term in order to get a lower monthly payment. That will mean more interest in the long run, but will give you some breathing room right now.

"I'm not a proponent of long car loans. But that's still better than a repossession," she said.

Bottom line

Ideally, you'll be able to pay off your loan quickly, or at least refinance it at a more favorable rate that allows you to put more money toward the principal balance.

Imagine not having a car payment. What could that extra few hundred dollars a month do for the bottom line? Make this the year that it happens.

MagnifyMoney is a price comparison and financial education website, founded by former bankers who use their knowledge of how the system works to help you save money.